CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

A millivoltmeter of 25 millivolt range is to be converted into an ammeter of 25-ampere range. The value (in ohm) of the necessary shunt will be:


A

1

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

0.01

No worries! We‘ve got your back. Try BYJU‘S free classes today!
C

0.05

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

0.001

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D

0.001


Step 1. Given data:

Range of millivoltmeter = 25 millivolt = 25×10-3 Volt

The expected range of ammeter i=25 ampere

Step 2. Calculating the value of shunt resistance

For making an ammeter, shunt resistance Rs is connected in parallel to the galvanometer.

Here, shunt resistance= Rs, Vg= galvanometer voltage, ig= full-scale deflection current,

Hence RS=Vgi-ig..........1, Where subscript g refers to the galvanometer,

Now ig=VgRg=25×10-3Rg

Here voltmeter's resistance = Rg

Now Rg, Because in an ideal voltmeter, R

Hence, ig0

Thus, from 1,

Rs=Vgi=25×10-325=0.001Ω

Thus, the correct option is option D.


flag
Suggest Corrections
thumbs-up
0
BNAT
mid-banner-image